Core B: Clinical Summary/Abstract Core B: Clinical recruits, assesses, and follows all participants in the ADRC Cohort. It uses well- established informant-based clinical and psychometric instruments (including the Uniform Data Set) at entry and annually thereafter to obtain clinical, cognitive, behavioral, and neurological data to carefully characterize each participant as to the presence or absence of dementia and, when present, its severity and etiology. The Core has successfully provided participants, tissue, and data to all requesting Cores and Projects since its inception in 1985 and will continue to do so in the next 5-year funding period. The Core's Specific Aims in the proposed funding period are: 1. Maintain the current active cohort of participants (current N=306), carefully characterized as to the presence or absence of symptomatic AD, to support longitudinal studies of the clinical, cognitive, and biomedical correlates of symptomatic AD in comparison with normal aging and to mark the transition of participants with preclinical AD to cognitive impairment. 2. Annually enroll and assess 20 new participants age 65Y or older, 10 CDR 0 and 10 with symptomatic AD at the CDR 0.5/1 stage, to replenish attritional losses and increase the cohort size to ~350 to meet the needs of the Projects and to ensure that participant burden is appropriately distributed 3. Provide clinical and cognitive data to all Cores and Projects, work closely with Data Management and Statistics and Administration Cores to coordinate data acquisition and management, and integrate Core activities with the scientific goals of the ADRC. 4. Collect biospecimens from participants (blood, CSF) as appropriate. 5. Refer all Core participants to HASD's Imaging Core for structural MRI, rs-fcMRI, and PET amyloid imaging with florbetapir at baseline and every 3 years thereafter. These imaging studies are funded at no cost to the ADRC by an executed contract with Avid Radiopharmaceuticals, a wholly owned subsidiary of Eli Lilly Company. 6. Support the Neuropathology Core through our voluntary brain autopsy consent program and obtain information about cognitive status at time of death to support clinicopathological correlations. 7. Support all proposed Projects in this application with clinically well-characterized participants and/or their data and biospecimens as follows: 8. Support the ADRC's contributions to national and international collaborative studies, including the National Alzheimer Coordinating Center, the Alzheimer's Disease Cooperative Study, ADNI, NCRAD, the Genetics Consortium for Late Onset Alzheimer's Disease, and the Alzheimer's Disease Genetics Consortium.